Minimally-invasive surgical techniques are aimed at reducing the amount of extraneous tissue that is damaged during diagnostic or surgical procedures, thereby reducing patient recovery time, discomfort, and deleterious side effects. As a consequence, the average length of a hospital stay for standard surgery may be shortened significantly using minimally-invasive surgical techniques. Also, patient recovery times, patient discomfort, surgical side effects, and time away from work may also be reduced with minimally-invasive surgery.
A common form of minimally-invasive surgery is endoscopy, and a common form of endoscopy is laparoscopy, which is minimally-invasive inspection and surgery inside the abdominal cavity. In standard laparoscopic surgery, a patient's abdomen is insufflated with gas, and cannula sleeves are passed through small (approximately one-half inch or less) incisions to provide entry ports for laparoscopic instruments.
Laparoscopic surgical instruments generally include an endoscope (e.g., laparoscope) for viewing the surgical field and tools for working at the surgical site. The working tools are typically similar to those used in conventional (open) surgery, except that the working end or end effector of each tool is separated from its handle by an extension tube (also known as, e.g., an instrument shaft or a main shaft). The end effector can include, for example, a clamp, grasper, scissor, stapler, cautery tool, linear cutter, or needle holder.
To perform surgical procedures, the surgeon passes working tools through cannula sleeves to an internal surgical site and manipulates them from outside the abdomen. The surgeon views the procedure from a monitor that displays an image of the surgical site taken from the endoscope. Similar endoscopic techniques are employed in, for example, arthroscopy, retroperitoneoscopy, pelviscopy, nephroscopy, cystoscopy, cisternoscopy, sinoscopy, hysteroscopy, urethroscopy, and the like.
Minimally-invasive telesurgical robotic systems are being developed to increase a surgeon's dexterity when working on an internal surgical site, as well as to allow a surgeon to operate on a patient from a remote location (outside the sterile field). In a telesurgery system, the surgeon is often provided with an image of the surgical site at a control console. While viewing a three-dimensional image of the surgical site on a suitable viewer or display, the surgeon performs the surgical procedures on the patient by manipulating master input or control devices of the control console. Each of the master input devices controls the motion of a servo-mechanically actuated/articulated surgical instrument. During the surgical procedure, the telesurgical system can provide mechanical actuation and control of a variety of surgical instruments or tools having end effectors that perform various functions for the surgeon, for example, holding or driving a needle, grasping a blood vessel, dissecting tissue, or the like, in response to manipulation of the master input devices.
Manipulation and control of these end effectors is a particularly beneficial aspect of robotic surgical systems. For this reason, it is desirable to provide surgical tools that include mechanisms that provide three degrees of rotational movement of an end effector to mimic the natural action of a surgeon's wrist. Such mechanisms should be appropriately sized for use in a minimally-invasive procedure and relatively simple in design to reduce possible points of failure. In addition, such mechanisms should provide an adequate range of motion to allow the end effector to be manipulated in a wide variety of positions. Such mechanisms typically include moving components (e.g., control cables, control rods) routed within the instrument shaft of the instrument to transmit actuation force/movement to the end effector.
Non-robotic linear clamping, cutting and stapling devices have been employed in many different surgical procedures. For example, such a device can be used to resect a cancerous or anomalous tissue from a gastro-intestinal tract. Unfortunately, many known surgical devices, including known linear clamping, cutting and stapling devices, often have opposing jaws that may be difficult to maneuver within a patient. For known devices having opposing jaws that are maneuverable within a patient, such devices may not generate sufficient clamping force for some surgical applications (e.g., tissue clamping, tissue stapling, tissue cutting, etc.), which may reduce the effectiveness of the surgical device.
Mechanisms that provide for articulation of an end effector and mechanisms that transmit actuation forces to an end effector can include a collection of components routed within an instrument shaft that supports the end effector. Such components may move laterally within the instrument shaft in response to articulation of the end effector. Such lateral displacement, however, presents significant problems with regard to preventing the insufflated gas and/or bodily fluids from traveling up the instrument shaft, thereby complicating instrument cleaning and/or making it difficult to maintain pneumo-peritineal pressure during use in endoscopic procedures.
Thus, there is believed to be a need for seals and sealing methods that prevent insufflated gas and/or bodily fluids from traveling up an instrument shaft of a laparoscopic surgical instrument that includes a laterally moving mechanism component routed within the instrument shaft.